Gage for thread-cutting tools



L. H.-S0|SSON.

GAGE FOR THREAD CUTTING TOOLS.

APPLICATION FILED MAY 24, 1915- Patented Aug. 22,1916.

mvamroz v Lam 5 9/660/V UNTTED %TATE% ATENT @FFTQE.

LOUIS H. SOISSON, 0F SCOTTDALE, PENNSYLVANIA.

GAGE FOR THREAD-CUTTING TOOLS.

Application filed May 24, 1915.

To all whom it may concern:

Be it known that 1, Louis H. Soissoiv, a citizen of the United States,residing at Scottdale, in the county of vVestmoreland and State ofPennsylvania, have invented certain new and useful Improvements in Gagesfor Thread-Cutting Tools, of which the following is a specification.

This invention relates in general to gages, and more particularly todevices of this character that are especially adapted to accurately gagethe size of tools used in cutting screw threads of different pitches, orin other words, furnish a correct standard for tools that are used indetermining the number of threads per linear inch.

In grinding down tools used to determine the character of a screwthread, it is essential that a positive and effective gage device beutilized to insure absolute accuracy.

To this end, the invention contemplates a novel and practical instrumentdesigned to be used when grinding threading tools to conform to thetwenty-nine degree Acme standard, and which is of simple 1 construction,easily manipulated, and readily capable of adjustment to the desiredpitch.

In this connection, the device also contemplates a construction wherebythe instrument may be set or adjusted so that only the desired number ofthreads per inch can be obtained from each particular adjustment,thereby providing a device that may be conveniently handled without thenecessity of making an adjustment every time that it is desired to gagethe tool, thus eliminating danger of error in grinding the tool, asmight occur if frequent adjustments were necessary. I

With the above and other objects in view which will more readily appearas the nature of the invention is better understood, the same consistsin the novel construction, combination and arrangement of partshereinafter more fully described, illustrated and claimed.

'A preferred embodiment of the invention is disclosed in theaccompanying drawing, wherein the device-is shown on a considerablyenlarged scale, and in which Figure 1 is a plan view of the device. Fig.2 is a section on the line 2--2 of Fig. 1. Fig. 3 is a perspective viewof the pitch disk.

Similar reference characters designate cor- Specification of LettersPatent.

Patented Aug. 22, 1916.

Serial No. 30,128.

responding parts throughout the several figures of the drawings.

A novel and distinctive feature of the invention resides in theemployment of a main gage disk, and a rotatable pitch disk, whichcooperate to provide a gage notch whereby the tool used for cuttingscrew threads may be accurately ground to conform with an adoptedstandard. That is to say, the invention proposes to utilize a memberhaving a notch of a predetermined included angle, preferably 29 toconform with the Acme standard, and a rotatable pitch member forcooperating with the notched member to give the different pitches, orthe number of threads per linear inch. As thread cutting tools vary inwidth at their point for different pitches or threads per inch, butretain the same angle for all pitches, it is proposed to bring aplurality of pitch or thread determining faces carried by the pitchmember into position across the notch to obtain the desired number ofthreads per inch.

Accordingly, the present invention is capable of embodiment in varioussizes and designs, and may be made of any material suitable for thepurpose, preferably thin metal, and in all cases essentially comprises amain gage disk 1, and a relatively adjustable pitch disk 2.

Referring to the characteristics of the main gage disk 1, it will beobserved, more particularly from Fig. 1 that the same is provided with aV-shaped notch 3, the side walls t of which converge inwardly from theperiphery of the disk, so as to form an angle of 29, thus conforming tothe requirements of the well-known Acme standard The apex of the notch 3opens into a sight opening 5, which is surrounded by an annulardepression or cupped portion 6 having a fixed designation 7 in the formof a straight line which indicates the center of the angle of the notch3.

The pitch disk 2 is carried by the main gage disk 1, and iseccentrically connected therewith by means of a pivot pin 8. For thepurpose of causing a frictional engagement between the disks 1 and 2,the pivot pin 8 is preferably threaded as at 9, and provided with aclamping nut 10, which is hollowed out at one end as at 11 to receiveand house a tension spring 12. In addition to providing for adjustingthe tension of the spring 12, the clamping nut 10 securely holds the twoplates in their adjusted position when the tool is in use.

Referring further to the novel features of the pitch disk 2, it will beobserved that the periphery thereof is of a substantially spiraldisposition, and is provided with a plurality of flat peripheral pitchfaces or pitch detern'lining faces 13 which may vary in numberaccrn'ding to the requirements of the device. That is to say, the numberof these faces may vary in each instrument according to the class ofwork to give the de sired or required number of threads required foreach linear inch. It will thus be apparent that since these flat pitchfaces 13 are arranged successively in spiral relation, they arenecessarily of different distances from the center of the pitch diskthereby being graduated to provide for adjusting the device to differentpitches. Accordingly, when the disks 1 and 2 are in their assembledrelation as shown in Figs. 1 and 2, the rotation of the disk 2 will varythe depth of the notch 3 for a distance equal to the difference indistance of each pitch face 13 from the center of the disk. The disk 2is preferably provided with a plurality of indicating marks 14: whichare so disposed that they indicate the center of the pitch faces, andare so arrznged that they will appear before the sight opening 5 in thedisk 1 to register with the fixed mark 7 thereon. This arrangementprovides for insuring the accuracy of the angles provided by thecooperating pitch faces 13 and sides 4: of the notch 3.

It is of course understood that the width of the end of the cutting toolis measured by the distance between the points (L-(6, and that thisdistance varies according to the pitch face disposed across the notch 3.That is to say, the distance aa. varies in accord ance with the radiusof the pitch face from the center of the disk 2. Thus, when a pitch faceof long radius is disposed across the notch, the points (6(t will befarther apart than when a pitch face of short radius is in operativeposition. In this v-.'ay, the de sired pitch or number of threads perlinear inch may be readily selected, and the end of the tool ground tofit accurately to the outlines of the pitch notch formed by thecooperating gage surfaces of the members 1 and 2. 7

It is thought that the manner of operating and using the present devicewill be readily apparent. However, it may be stated in this connectionthat the varying pitches are selected by merely rotating the disk :2 sothat the fixed mark of the selected pitch face is made to register withthe fixed mark on the disk 1, thus bringing the selected pitch face intooperative position across the notch. The relative movements of the diskare effected by slightly unloosening the screw 10, and to hold the disksin their adjusted positions, this same screw may be tightened.Accordingly, if it is desired, for example, to cut a six-pitch thread orSIX threads per inch, the pitch disk 2 is revolved until the pitch facecorresponding to the designation 6 on the pitch disk appears in thesight opening 5. The center line 7 and thein dication mark 6 designatedin Fig. 3 as 1% must then coincide, and the disks are heln in theiradjusted position by the clamping nut 10. The thread cutting tool isthen ground to conform to the opening 3 formed by the sides 4: of thenotch, and the pitch face 13 corresponding to the number of threads perinch, in the present example 6. Thus, a tool ground to fit the notch forthis adjustment will cut a screw having six threads to the inch. In thisconnection, it will be understood that the pitch or width of the toolmay be gaged by revolving the pitch disk :2 so that the desired pitchface will come across the notch 8, and thus cooperate with the sides 4of the notch to give the desired pitch or number of threads per linearinch. The present device is therefore capable of gaging a tool to cutanywhere from 1 to 10 threads per linear inch, but it will of course beunderstood that by increasing the number of pitch faces arrangedsuccessively in spiral relation, that the number of threads per inch canbe increased.

\Vithout further description, it is thought that the features andadvantages of the present invention will be readily apparent to thoseskilled in the art, and it will be readily understood that minor changesin the details of construction may be resorted to without departing fromthe spirit of the invention or scope of the appended claims.

I claim:

1. A gage for sizing thread cutting tools comprising a main gage memberhaving a permanently open notch in its edge the walls of the notchconverging as the depth increases, and a relatively adjustable membercarried by the said main gage member and provided with a plurality oftool abutment faces at variable distances from the point of support ofthe adjustable member, said faces being adapted to be separatelypositioned across the notch to form the bottom thereof.

2. A gage for sizing thread cutting tools comprising a main gage memberhaving a notch, and means eccentrically pivoted to said main gage memberand having a plurality of flat pitch determining faces for varying thedepth of said notch.

3. A gage for sizing thread cutting tools comprising a main gage memberhaving a V-notch, and means pivotally connected to said main gage memberhaving a plurality of flat pitch determining" faces, said faces beingarranged successively at different. dis.

tances from the point of pivotal connection of said means with the maingage member to vary the depth of said V-notch.

4. A gage for sizing thread cutting tools comprising a main gage diskhaving a V- notch, and a pitch disk pivotally carried by said gage diskand having in its periphery a plurality of flat pitch faces cooperatingwith said \l-notch.

, 5. A gage for sizing thread cutting tools comprising a main gage diskhaving a V- notch, said notch having a sight opening at its apex and afixed mark for indicating its center, a pitch disk eccentrically pivotedto LOUIS H. SOISSON.

Witnesses P. L. BROWN,

KATHRYN PHELAN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents, Washington, D. G.

